Safety sledge-hammer

ABSTRACT

This invention is a hammer adapted for the safe driving of long rods into the earth. Building codes require long rods drive into the ground for temporary and permanent ground connections for electric systems, or rods or pipe for marking surveyed locations. This hammer is provided with a cavity in one impact end in order to avoid outside misses dangerous to the person temporarily holding the rod. The cavity has conical walls for guiding the end of the rod or pipe which often vibrates out of exact alignment with the path of movement of the hammer head.

nited States Patent 11 1 Schera, Jr. Jan. 22, 197 1 [5 1 SAFETYSLEDGE-HAMMER 3,019,827 2/1962 Jeffery et al. 145/36 Inventor: Enos L- gJr-, 5 SW 37 FOREIGN PATENTS OR APPLICATIONS 714,794 9 1954 GreatBritain 145/36 [22] Filed: Nov. 6, 1972 Primary Examiner-James L. Jones,Jr. [21] Appl' 304048 Assistant ExaminerJ. T. Zatarga Attorney, Agent,or Firm-Lloyd J. Andres [52] US. Cl 145/29 R, 145/36, 173/90 [51] Int.Cl. Bc 1/00 [58] Field 61 sear-611 145/29 R, 29 A, 29 B, 29 c, [57]ABSTRACT 145/29 D, 30.5, 36, 173/90; 254/26 This invention is a hammeradapted for the safe driving of long rods into the earth. Building codesrequire [56] References Cited long rods drive into the ground fortemporary and per- UNITED STATES PATENTS manent ground connections forelectric systems, or 538,382 4/1895 Petree .1 145/29 R rods of P f"mafking i i h 846 503 3/1907 Pamer 145,29 B hammer 1s prov1ded w1th acavity In one Impact end In 1,122Z506 12/1914 Keating 145 29 A Orderavoid utside misses dangerous t0 the Person 1,496,013 6/1924 Minick145/29 A temporarily holding the The cavity has Conical 1,737,64712/1929 Cummings 145/29 D walls for guiding the end of the rod or pipewhich 2,086,694 7/1937 Beegle 145/29 A often vibrates out of exactalignment with the path of 2,833,323 5/1958 Strickland l/29 A movementof the hammer head, 2,917,349 12/1959 Saylor et al. /29 R 2,980,1544/1961 Williamson 145/29 R 5 Claims, 5 Drawing Figures 1 SAFETYSLEDGE-HAMMER This invention relates in general to hammers and moreparticularly to a sledge-hammer with a predetermined cavity in theimpact and thereof for driving relatively long flexible rods or pipeinto the earth for a ground connection for electric circuits which arerequired by code authorities.

Prior sledge-hammers for driving rods into the earth required the userof the hammer to be suspended on a ladder and a second man for holdingthe rod in predetermined vertical alignment. Very often a miss" on thepart of the user will inflict injury upon the person holding the rod,even when holding tools are used. This miss is often due to thevibratory nature of the relatively small diameter rod used for thispurpose.

A principal object of the hammer is the provision of a cavity in oneimpact end of the hammer head. The opposite end of the hammer head issubstantially flat for normal inverted use.

A principal object of the hammer is the provision of a cavity in oneimpact end of the hammer head. The opposite end of the hammer head issubstantially flat for normal inverted use.

Since special rods and sometimes pipe are used for ground connectioncircuits there is also variance in the cross sectional diametersthereof, hence the cavity in the safety impact end has a flat bottom anddivergent conical wall to provide a degree of self alignment when theend of the rod is struck.

These and other objects and advantages in one embodiment of theinvention are described and shown in the following specification anddrawing, in which:

FIG. 1 is a perspective view in reduced scale of a sledge-hammerincorporating a cavity in one impact end thereof.

FIG. 2 is an enlarged cross sectional view taken through section line2-2, FIG. 1.

FIG. 3 is an end illustration of a rod being driven into the earth withthe hammer shown in FIG. 1, with a portion of the hammer head brokenaway.

FIG. 4 is a perspective view in reduced scale of an alternate singlehand hammer for use in driving smaller rods predetermined depths into amedia.

FIG. 5 is a side elevation of a hammer head with a portion broken awayshowing a replaceable impact end.

Referring to FIG. 1, a sledge-hammer head 1, usually made from forgedsteel, has a special impact portion 2 on one end thereof, with a cavity3 therein, to be hereinafter described. The opposite end surface 4 ofthe head 1 is planar and may be used for normal work. A two-hand handle5 has one end portion 6 secured in a transverse hole through the head bya well known wedge means 7.

FIG. 2 illustrates the cavity 3 with the wall thereof having the shapeof a frustrum of a cone terminating in a planar impact surface parallelthe opposite surface 4.

FIG. 3 illustrates the manner in which a long rod 8, such as a copperclad ground rod having a length of approximately ten feet, is driven inthe earth in the direction shown by arrow by the impact surface withinthe cavity 3. It is apparent that long rods, even when held by a personshand or a tool, are subject to misalignment due to vibration or othercauses where an impact surface would deflect from the rod with the riskof damage to the holder of the rod.

FIG. 4 illustrates a smaller single hand hammer of alternateconstruction, for driving smaller objects, with a cavity 3a applied toone end of the head in the same manner as applied to the head shown inFIG. 1.

FIG. 5 illustrates an alternate construction in a hammer having a head1b with a normal planar driving surface 9 with the opposite end having acentral threaded bore 10 for receiving a mated replacement head 11having a threaded projection 12 for tightly mating the paralleltransverse surfaces of the head lb and replacement head 11. The impactmember is replaceable not only for cavities of different size to driverods or pipes of different diameters, but also when the interior wall orthe impact surface of the hammer is damaged.

It is to be understood that certain modifications in construction areintended to come within the teachings and scope of the abovespecification.

Having described my invention, 1 claim:

1. A sledge-hammer for driving relatively long linear objects comprisingan elongated head of predetermined shape and weight,

said head symmetrical about a longitudinal central axis with theopposite end surfaces of said head normal said axis and including a holethrough said head intersecting and normal said axis between saidopposite surfaces including securing means for retaining an end portionof a substantially straight handle of predetermined dimensions for thesimultaneous use of both right and left hands, cavity of predetermineddimensions and having conical convergent sloping side wall in one end ofsaid end surfaces coaxial with and terminating at a predetermined depthforming a planar impact surface normal said axis.

2. The construction recited in claim 1 wherein said head is generallyrectangular in cross section and having predetermined beveledlongitudinal corners.

3. The construction recited in claim 1 wherein said head is generallycylindrical in shape with the edges of the said end surfaces having achamfer of predetermined size and shape.

4. The construction recited in claim 1 including a predetermined chamferin all angle junctions.

5. The construction recited in claim 1 wherein the size of said head andsaid handle are substantially proportionately reduced for providing foruse by one hand.

1. A sledge-hammer for driving relatively long linear objects comprisingan elongated head of predetermined shape and weight, said headsymmetrical about a longitudinal central axis with the opposite endsurfaces of said head normal said axis and including a hole through saidhead intersecting and normal said axis between said opposite surfacesincluding securing means for retaining an end portion of a substantiallystraight handle of predetermined dimensions for the simultaneous use ofboth right and left hands, a cavity of predetermined dimensions andhaving conical convergent sloping side wall in one end of said endsurfaces coaxial with and terminating at a predetermined depth forming aplanar impact surface normal said axis.
 2. The construction recited inclaim 1 wherein said head is generally rectangular in cross section andhaving predetermined beveled longitudinal corners.
 3. The constructionrecited in claim 1 wherein said head is generally cylindrical in shapewith the edges of the said end surfaces having a chamfer ofpredetermined size and shape.
 4. The construction recited in claim 1including a predetermined chamfer in all angle junctions.
 5. Theconstruction recited in claim 1 wherein the size of said head and saidhandle are substantially proportionately reduced for providing for useby one hand.